Dishwasher and fan

ABSTRACT

A dishwasher includes a cabinet defining a washing chamber, a door for closing an opening of the washing chamber and a fan for exhausting moist air from the washing chamber. The fan is arranged between an outer wall and an inner wall of the door, in fluid communication with the washing chamber via at least one vent hole formed in the inner wall, and includes a housing with an inlet and an outlet, an impeller in the housing and an electric motor for driving the impeller. The fan is arranged such that an axial direction of the motor is perpendicular to the inner wall. A flange is formed at an edge of the inlet to restrict water from entering the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Applications No. 201410013161.4 and No. 201410013176.0 both filed in The People's Republic of China on Jan. 10, 2014, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to a dishwasher and in particular, to a fan for the dishwasher for exhausting moist air from the washing chamber of the dishwasher.

BACKGROUND OF THE INVENTION

A dishwasher typically includes a washing chamber, a door for closing an opening of the washing chamber, a sump for storing wash water, spray nozzles for spraying wash water, a heater for heating the wash water, and a fan for exhausting moist air from the washing chamber via a discharge duct which is in fluid communication with the sump.

In a known dishwasher, the fan is arranged between the outer wall and the inner wall of the door and water sprayed by the nozzles might enter into the fan. When the door is closed the discharge duct is connected to the sump to return water sprayed into the fan back to the sump. However, when the door is open, the discharge duct is disconnected from the sump and water in the duct will leak to the floor, worsening the sanitation condition in the kitchen.

Hence there is a desire for a dishwasher with less or no sprayed water entering into the fan.

SUMMARY OF THE INVENTION

Accordingly, in one aspect thereof, the present invention provides a dishwasher, comprising: a cabinet which defines a washing chamber; a door for opening and closing an opening of the washing chamber; and a fan for exhausting moist air from the washing chamber, the fan being arranged between an outer wall and an inner wall of the door, in fluid communication with the washing chamber via at least one vent hole formed in the inner wall, and comprising a housing with an inlet and an outlet, an impeller disposed in the housing, and an electric motor for driving the impeller; wherein a flange is formed at an edge of the inlet for blocking water from entering the housing.

Preferably, an inner diameter of the flange gradually decreases in a direction from the edge of the inlet towards the impeller.

Preferably, a bottom inner surface of the flange in the vertical direction forms an inclined angle θ that is less than 45 degrees relative to the axial direction of the motor.

Preferably, the flange extends axially from the edge of the inlet.

Preferably, the distance between the flange and the inner wall is less than 0.5 mm.

Preferably, the housing comprises a base with a side plate, and a cover assembled to the base and having a ring wall extending from one axial end surface of the cover facing the inner wall, the inlet being formed in the cover; wherein a groove is formed between the ring wall and the side plate; and a seal ring in water-tight contact with the inner wall is disposed in the groove.

Preferably, the distance between the flange and the inner wall is greater than the distance between the ring wall and the inner wall.

Preferably, the flange extends outwardly from the edge of the inlet towards the inner wall.

Preferably, the flange extends inwardly from the edge of the inlet towards the impeller.

Preferably, the flange extends from the edge of the inlet on both axial sides of the cover.

Preferably, a ratio between the distance D between the flange and the inner wall and an axial length L of the flange is less than 10%.

Preferably, the fan is disposed such that an axial direction of the motor is perpendicular to the inner wall.

According to a second aspect, the present invention provides a fan of a dishwasher for exhausting moist air from a washing chamber of the dishwasher, comprises a housing with an inlet and an outlet, an impeller disposed in the housing, and an electric motor for driving the impeller; wherein a flange is formed at an edge of the inlet for blocking water from entering the housing.

Preferably, an inner diameter of the flange gradually decreases in a direction from the edge of the inlet towards the impeller.

Preferably, an inner surface of the flange forms an inclined angle θ that is less than 45 degrees relative to an axial direction of the motor.

Preferably, the flange extends axially from the edge of the inlet.

Preferably, the motor is a low voltage direct current motor with an input voltage of less than 60V and an output power of less than 0.5 Watt.

Preferably, the flange extends outwardly from the edge of the inlet.

Preferably, the flange extends inwardly from the edge of the inlet towards the impeller.

Preferably, the flange extends from the edge of the inlet on both axial sides of the cover.

Preferably, the flange has an axial length L that is greater than 2 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example only, with reference to figures of the accompanying drawings. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same reference numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.

FIG. 1 is a schematic representation of a dishwasher in accordance with a preferred embodiment of the present invention;

FIG. 2 is a sectional view of a fan and an inner wall of a door of the dishwasher of FIG. 1;

FIG. 3 illustrates a cover of the fan of FIG. 2;

FIG. 4 is an enlarged view of a part of FIG. 2;

FIG. 5 is a sectional view of the cover of the fan in accordance with another embodiment of the present invention;

FIG. 6 is a sectional view of the cover of the fan in accordance with yet another embodiment of the present invention; and

FIG. 7 is a sectional view of an electric motor of the fan of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic representation of a dishwasher 10 in accordance with an embodiment of the present invention. The dishwasher 10 includes a cabinet 16, a washing chamber 22 disposed within the cabinet 16, a sump (not shown in the figure) at the bottom of the washing chamber 22 for storing wash water and an opening for adding and removing items to be washed. A door 20 is arranged to close the opening in the washing chamber 22 and a fan 24 is located within the door, between the outer wall 12 and the inner wall 14, for drying the inside of the washing chamber 22. The washing chamber 22 is provided with baskets (not shown in the figure) for receiving objects to be washed, spray nozzles (not shown in the figure) for spraying wash water, and a heater (not shown in the figure) for heating the wash water. The fan 24 is preferably arranged at the upper portion of the door 20. Moist air in the washing chamber 22 is extracted from the washing chamber 22 via the discharge duct 26.

FIG. 2 is a sectional view of the fan 24 and the inner wall 14 of the door 20. The fan 24 comprises a fan housing with a base 30 and a cover 32 assembled to each other, an impeller 34 disposed in the fan housing, and an electric motor 36 for driving the impeller 34. Preferably, the fan 24 is arranged such that the shaft 48 of the motor 36 is perpendicular to the inner wall 14 of the door 20, with the inlet 38 of the fan 24 facing vent holes 40 in the inner wall 14.

The base 30 of the fan housing has a bottom plate 42 and an annular side plate 44 axially extending from the outer periphery of the bottom plate 42. The motor 36 is received in a motor sleeve 46 extending from the center of the bottom plate 42. The shaft 48 of the motor 36 passes through the bottom plate 42 and enters into the fan housing to connect with the impeller 34. The side plate 44 of the base 30 has an outlet 50. Preferably, the outlet 50 extends downwardly in the radial direction and is connected to the discharge duct 26.

FIG. 3 illustrates the cover 32 of the fan 24. FIG. 4 is an enlarged view of a part of FIG. 2 showing part of the fan 24 and the inner wall 14 of the door 20. The cover 32 is assembled to the base 30 and comprises a circular disk body 52 and a ring wall 56 that extends from the outer periphery 54 of one axial end surface of the disk body 52 facing the inner wall 14 of the door 20. The ring wall 56, the axial end portion 58 of the side plate 44 of the base 30 adjacent the inner wall 14, and the outer periphery 54 of the disk body 52 define an annular groove 60. A seal ring 62 is disposed inside the annular groove 60 and in water-tight contact with the inner wall 14. Thus, the fan housing and the inner wall 14 of the door 20 are sealingly connected to each other so as to prevent the heated moist air, after flowing through the vent holes 40, from leaking from a gap between the fan housing and the inner wall 14 of the door 20. The inlet 38 has an edge 39 which is the inner surface of the opening formed at the center of the cover 32. That is, the edge 39 is the inner edge of the disk body 52. A flange 64 is formed at the edge 39. In this embodiment, the flange 64 axially extends from the edge 39 on both axial sides of the disk body 52. Preferably, the distance D between the flange 64 and the inner wall 14 is smaller than 0.5 mm. By this configuration, at least some of the wash water sprayed by the nozzle, that passes through the vent holes 40, is blocked by the flange 64 from entering the fan housing via the inlet 38. The flange 64 does not extend as far as the ring wall 56, such that the distance between the outer axial end surface 66 of the flange 64 and the inner wall 14 is greater than the distance between the outer axial end surface 68 of the ring wall 56 and the inner wall 14.

Preferably, the flange 64 has an axial length L greater than 2 mm. The ratio of the distance D between the flange 64 and the inner wall 14 and the axial length L of the flange 64 is smaller than 10%.

Preferably, the motor 36 is a low voltage direct current (LVDC) motor. The input voltage of the LVDC motor is less than 60V and the output power of the LVDC motor is less than 0.5 Watt. Compared to the brushless direct current (BLDC) motor and the shaded pole motor in traditional fans, the performance of the LVDC motor fan is better and the cost of the LVDC motor fan is less as no controller is required. Below table 1 is a comparison of the dishwashers using the three different types of motor. In the table, “3” means the test result is the best, “1” means the test result is the worst. The table shows the LVDC motor in the present invention has advantages in controllability, safety, system cost and efficiency.

TABLE 1 Noise System Controll- Motor System Efficiency cost ability Safety noise noise Lifespan Size Total LVDC 3 3 3 3 1 2 2 2 19 Motor BLDC 2 1 1 2 3 3 3 3 18 Motor Shaded 1 2 3 1 2 1 3 1 14 Pole Motor

FIG. 5 illustrates the cover 32 of the fan in accordance with another embodiment of the present invention. The cover 32 is arranged in the vertical direction in use. In this embodiment, the flange 64 extends from the edge 39 of the inlet 38 (or disk body 52) towards the impeller 34 and the inner diameter of the flange 64 gradually decreases along this direction. The bottom inner surface 70 of the flange 64 in the vertical direction forms an inclined angle θ relative to the axial direction. The angle θ is preferably smaller than 45 degrees. By this configuration, as shown by the arrows in the figure, water sprayed by the nozzle, after hitting the top inner surface 72 of the flange 64, will fall down onto the bottom inner surface 70 and then flow out of the inlet along the downwardly sloping surface.

FIG. 6 illustrates the cover 32 of the fan in accordance with yet another embodiment of the present invention. The cover 32 is arranged in the vertical direction in use. In this embodiment, the flange 64 extends from the edge 39 of the inlet 38 on both axial sides of the disk body 52 and the inner diameter of the flange 64 gradually decreases along the direction from the edge 39 towards the impeller 34. The bottom inner surface 70 of the flange 64 in the vertical direction forms an inclined angle θ, preferably smaller than 45 degrees, relative to the axial direction. In this embodiment, the radial outer surface of the flange 64 at the axial outer side of the disk body 52 can block water running down the disk body 52 from entering the inlet 38 and the radially inner surface of the flange 64 can guide water hitting the top inner surface 72 to go outside of the fan housing along the downwardly sloping surface formed by the bottom inner surface 70 of the flange 64.

FIG. 7 illustrates the motor 36. The motor 36 is a low voltage direct current (LVDC) motor with a rotor and a stator surrounding the rotor. The rotor comprises a shaft 48, a rotor core 82 fixed on the shaft 48, a commutator 84 fixed on the shaft 48 adjacent the rotor core 82, rotor windings (not shown in the figure) wound about poles of the rotor core 82 and electrically connected to the commutator 84. Outer surfaces of the rotor poles form a circle. Slots are formed between adjacent rotor poles for accommodating the rotor windings. The stator comprises an axially extending round housing 86 having an open end and a closed end, at least one permanent magnet 88 fixed to the inner surface of the housing 86 and an end cap 90 closing the open end of the housing 86. Brushes 92 connected to an external LVDC power, preferably lower than 60 V, via electrical terminals (not shown in the figure) are supported by the end cap 90 for making sliding contact with the commutator 84 to supply power to the rotor windings. The shaft 48 is rotatably supported by two bearings 94 received in bearing holders 96 at each end of the motor.

In the description and claims of the present application, each of the verbs “comprise”, “include”, “contain” and “have”, and variations thereof, are used in an inclusive sense, to specify the presence of the stated item or feature but do not preclude the presence of additional items or features.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of example only and various modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined by the appended claims. 

1. A dishwasher, comprising: a cabinet which defines a washing chamber; a door for closing an opening of the washing chamber; and a fan for exhausting moist air from the washing chamber, the fan being arranged between an outer wall and an inner wall of the door, in fluid communication with the washing chamber via at least one vent hole formed in the inner wall, and comprising a housing with an inlet and an outlet, an impeller disposed in the housing and an electric motor for driving the impeller; wherein a flange is formed at an edge of the inlet for blocking water from entering the housing.
 2. The dishwasher of claim 1, wherein an inner diameter of the flange gradually decreases along a direction from the edge of the inlet towards the impeller.
 3. The dishwasher of claim 2, wherein a bottom inner surface of the flange in the vertical direction forms an inclined angle θ that is less than 45 degrees relative to the axial direction of the motor.
 4. The dishwasher of claim 1, wherein the flange axially extends from the edge of the inlet.
 5. The dishwasher of claim 1, wherein the distance between the flange and the inner wall is less than 0.5 mm.
 6. The dishwasher of claim 1, wherein the housing comprises a base with a side plate, and a cover assembled to the base and having a ring wall extending from one axial end surface of the cover facing the inner wall, the inlet being formed on the cover; a groove is formed between the ring wall and the side plate; and a seal ring in water tight contact with the inner wall is disposed in the groove.
 7. The dishwasher of claim 6, wherein the distance between the flange and the inner wall is greater than the distance between the ring wall and the inner wall.
 8. The dishwasher of claim 1, wherein the flange extends outwardly from the edge of the inlet towards the inner wall.
 9. The dishwasher of claim 1, wherein the flange extends inwardly from the edge of the inlet towards the impeller.
 10. The dishwasher of claim 1, wherein the flange extends from the edge of the inlet towards both axial sides of the cover.
 11. The dishwasher of claim 1, wherein a ratio between the distance D between the flange and the inner wall and an axial length L of the flange is less than 10%.
 12. The dishwasher of claim 1, wherein the fan is disposed such that an axial direction of the motor is perpendicular to the inner wall.
 13. A fan of a dishwasher for exhausting moist air from a washing chamber of the dishwasher, comprises a housing with an inlet and an outlet, an impeller disposed in the housing, and an electric motor for driving the impeller; wherein a flange is formed at an edge of the inlet for blocking water from entering the housing.
 14. The fan of claim 13, wherein an inner diameter of the flange gradually decreases along a direction from the edge of the inlet towards the impeller.
 15. The fan of claim 14, wherein an inner surface of the flange forms an inclined angle θ that is less than 45 degrees relative to an axial direction of the motor.
 16. The fan of claim 13, wherein the flange extends axially from the edge of the inlet.
 17. The fan of claim 13, wherein the motor is a low voltage direct current motor with an input voltage of less than 60V and an output power of less than 0.5 Watt.
 18. The fan of claim 13, wherein the flange extends outwardly from the edge of the inlet.
 19. The fan of claim 13, wherein the flange extends inwardly from the edge of the inlet towards the impeller.
 20. The fan of claim 13, wherein the flange extends from the edge of the inlet on both axial sides of the cover.
 21. The fan according to claim 20, wherein an inner diameter of the flange gradually decreases in a direction from the edge of the inlet towards the impeller.
 22. The fan according to claim 13, wherein the flange has an axial length L that is greater than 2 mm. 